Abstract

Obesity is a major public health challenge. Modeling growth and identifying children at risk of being overweight in early life is essential for effective prevention and intervention. To date, longitudinal studies from birth to adolescent are rare, and crucial period in childhood for overweight in future life is unclear. In addition, apart from known risk factors of overweight or obesity, further research on other potential risk factors is necessary. Even though it is well accepted that obesity is mainly a consequence of an unbalanced energy status, the impact of specific food item or food group on growth has long been controversial, which calls for more efforts.
In order to contribute to the aforementioned questions and research problems, we conducted a series of studies using data from two ongoing German birth cohorts. 1) Using longitudinal anthropometric data from birth to 5 years, we established a 10-year-overweight prediction model. Our results suggest that from 5 years onwards being overweight become predictive for 10-year overweight. 2) We investigated the association between mode of delivery and childhood obesity using cross-sectional data at age 2, 6 and 10 years. Children delivered by cesarean section were more likely to be obese at 2 years compared to those delivered vaginally, but not at age 6 and 10 years. These results do not support the hypothesis that increasing rates of cesarean section contribute to the childhood obesity epidemic. 3) We analyzed data from food frequency questionnaires which were completed during the 10-year follow-up, where we grouped 82 food items into 11 food groups. Our results suggest that intakes of meat, fish and beverages are important correlates of body weight status. In contrast, confectionery intake conversely associated with being overweight. Further study on the influence of possible reverse causation is needed. 4) We investigated the association between maternal BMI and child food intake at the age of 10 years. Our results suggest that maternal BMI and maternal overweight are important correlates of a child’s intake of energy, meat and eggs. Potential impact of mother’s weight status should be considered in diet counseling. Moreover, mother’s participation in dietary counseling might be helpful to improve offspring diet pattern and weight status.
These studies contributed to the current knowledge on early identification of children at risk of overweight and the potential influence of diet. In addition, our results suggest more efforts on longitudinal studies and more attention on reverse causation and misreport in dietary assessments in future studies.